6 ms·

> That it currently do not work economically is the issue that the article showcase. It's more than that. We simply don't live in a world where physics is in f

> That it currently do not work economically is the issue that the article showcase. It's more than that. We simply don't live in a world where physics is in favor for doing this. Many people have done more than back of the envelope calculations to show this simply was a non starter. Those (people who took money to build ) push this idea are either ignorant at best and dishonest at worst.

Wowfunhappy 7y ago
I do wonder if the concept could work on a sidewalk, given that they aren't being perpetually driven over by 3,000+ pound vehicles.
- CydeWeys 7y ago
  Water drainage is still going to be a big problem, as is damage/scratching caused by shoes, bicycle kickstands, trolleys, anything else with wheels that is pushed/pulled, you name it. Plus the simple fact that most sidewalks (at least here in the city) are often in the shadows of buildings. It only makes sense to start thinking about sidewalks once you've covered all the roofs, which are way better in every sense.
- ars 7y ago
  The ground pressure from a truck is around 150 PSI. A woman wearing high heels can match, and even exceed that. So the sidewalk would need to be just as strong as the road.
  - egdod 7y ago
    The woman in heels doesn’t ever slam on her brakes and skid.
    - asdfasgasdgasdg 7y ago
      That applies sheer stress to the road, but it doesn't really impact the compressive force or pressure applied, right?
  - mensetmanusman 7y ago
    Surprised this is getting down voted, this is a common example in physics 101 describing the concept of point pressure. Architects have to consider the point pressure of heels when designing certain walkways.
    - RadioHacker 7y ago
      I think it's getting downvoted because why does it have to be a _woman_ who's wearing the high heels?
  - kbutler 7y ago
    Common physics example, but it disregards how women actually walk and stand in heels. They walk on their forefoot, rather than balancing their weight on the heel. https://www.semanticscholar.org/paper/The-higher-the-heel-the-higher-the-in-ten-healthy-Speksnijder-Munckhof/9547d261aea7401caad230ecca180363ff13f0b4/figure/1 https://www.semanticscholar.org/paper/The-higher-the-heel-th... Shows less than 30 N/cm^2 (40 PSI) for women in heels - and higher heels result in lower heel pressure. Forefoot pressure is higher, despite the larger surface area.
    - reitzensteinm 7y ago
      Yeah, and a heel surface area of 32.3 +/- 4.4 cm^2. There are shoes with heel surface area of sub 1cm^2. I don't think the study invalidates parents claim, if anything it more it less supports it.
    - mbrumlow 7y ago
      Even so. It would be a flaw to not consider that at some point in time a women may put full force on the heel. Thus the example is valid. Also I have seen high hees being abused by walking mostly on the heel.
  - mirimir 7y ago
    It's not that simple. Looking at the damaged roadway, I see lots of punctate damage. That puzzled me until I read your comment. I'm pretty sure that it's gravel under truck tires. So the same force-concentration dynamic as high heels.
  - pjc50 7y ago
    Not only that, a common problem round here (UK) is that trucks park partially on the pavement. They routinely crack two-inch/50mm thick concrete paving slabs. I'd like to see a solar panel that can withstand that.
- tom_mellior 7y ago
  Sidewalks are still flat on the ground, which is not great in much of the world (like Normandy) where sunlight comes in at an angle. You would still get some generation, but would it be worth it compared to cells mounted elsewhere at a better angle, with less need for hardening, and less accumulation of dirt? Doing this on the sidewalks would add a lot of costs and complications.
- cs02rm0 7y ago
  Maybe a motorway hard shoulder would be preferable to a live lane.
- zimpenfish 7y ago
  There's a solar bike path in Holland which did pretty well. Exceeded expected yield the first two years but then dropped back to slightly under. https://en.solaroad.nl/wp-content/uploads/sites/2/prf1-ENG-SolaRoadKit-RESULTAAT-A4liggend.pdf https://en.solaroad.nl/wp-content/uploads/sites/2/prf1-ENG-S...
  - tinco 7y ago
    It didn't do well, they just marketed the failure as a success, and they were at scamming a different municipality for a follow up 'experiment'. Why can't they just work on something that makes sense?
- flukus 7y ago
  Better to build it above the sidewalk where it can be angled more efficiently and provide people with some sun/rain shelter.

Wowfunhappy 7y ago

I do wonder if the concept could work on a sidewalk, given that they aren't being perpetually driven over by 3,000+ pound vehicles.

CydeWeys 7y ago
Water drainage is still going to be a big problem, as is damage/scratching caused by shoes, bicycle kickstands, trolleys, anything else with wheels that is pushed/pulled, you name it. Plus the simple fact that most sidewalks (at least here in the city) are often in the shadows of buildings. It only makes sense to start thinking about sidewalks once you've covered all the roofs, which are way better in every sense.
ars 7y ago
The ground pressure from a truck is around 150 PSI. A woman wearing high heels can match, and even exceed that. So the sidewalk would need to be just as strong as the road.
- egdod 7y ago
  The woman in heels doesn’t ever slam on her brakes and skid.
  - asdfasgasdgasdg 7y ago
    That applies sheer stress to the road, but it doesn't really impact the compressive force or pressure applied, right?
- mensetmanusman 7y ago
  Surprised this is getting down voted, this is a common example in physics 101 describing the concept of point pressure. Architects have to consider the point pressure of heels when designing certain walkways.
  - RadioHacker 7y ago
    I think it's getting downvoted because why does it have to be a _woman_ who's wearing the high heels?
- kbutler 7y ago
  Common physics example, but it disregards how women actually walk and stand in heels. They walk on their forefoot, rather than balancing their weight on the heel. https://www.semanticscholar.org/paper/The-higher-the-heel-the-higher-the-in-ten-healthy-Speksnijder-Munckhof/9547d261aea7401caad230ecca180363ff13f0b4/figure/1 https://www.semanticscholar.org/paper/The-higher-the-heel-th... Shows less than 30 N/cm^2 (40 PSI) for women in heels - and higher heels result in lower heel pressure. Forefoot pressure is higher, despite the larger surface area.
  - reitzensteinm 7y ago
    Yeah, and a heel surface area of 32.3 +/- 4.4 cm^2. There are shoes with heel surface area of sub 1cm^2. I don't think the study invalidates parents claim, if anything it more it less supports it.
  - mbrumlow 7y ago
    Even so. It would be a flaw to not consider that at some point in time a women may put full force on the heel. Thus the example is valid. Also I have seen high hees being abused by walking mostly on the heel.
- mirimir 7y ago
  It's not that simple. Looking at the damaged roadway, I see lots of punctate damage. That puzzled me until I read your comment. I'm pretty sure that it's gravel under truck tires. So the same force-concentration dynamic as high heels.
- pjc50 7y ago
  Not only that, a common problem round here (UK) is that trucks park partially on the pavement. They routinely crack two-inch/50mm thick concrete paving slabs. I'd like to see a solar panel that can withstand that.
tom_mellior 7y ago
Sidewalks are still flat on the ground, which is not great in much of the world (like Normandy) where sunlight comes in at an angle. You would still get some generation, but would it be worth it compared to cells mounted elsewhere at a better angle, with less need for hardening, and less accumulation of dirt? Doing this on the sidewalks would add a lot of costs and complications.
cs02rm0 7y ago
Maybe a motorway hard shoulder would be preferable to a live lane.
zimpenfish 7y ago
There's a solar bike path in Holland which did pretty well. Exceeded expected yield the first two years but then dropped back to slightly under. https://en.solaroad.nl/wp-content/uploads/sites/2/prf1-ENG-SolaRoadKit-RESULTAAT-A4liggend.pdf https://en.solaroad.nl/wp-content/uploads/sites/2/prf1-ENG-S...
- tinco 7y ago
  It didn't do well, they just marketed the failure as a success, and they were at scamming a different municipality for a follow up 'experiment'. Why can't they just work on something that makes sense?
flukus 7y ago
Better to build it above the sidewalk where it can be angled more efficiently and provide people with some sun/rain shelter.